Rubbing or polishing machine.



PATBNTED MAY 24, 1904. 0. s. YARNELLP RUBBING 0 POLISHING MACHINE.APPLIUATION FILED OCT. 31. 1903.

N0 MODEL.

3 SHBETS SHEET 1.

51 v r W F W I! I) BATENTED MAY 24,- 1904.

0. s'. YARNELL. RUBBING 0R POLISHING MACHINE.

APPLICATION IILBDIOOT; l. 1903.

3 SHEETS-SHEET 2.

N0 MODEL.

cu e M2 No. 761,023. PATENTED MAY 24, 1904.

' c. s. YARNELL'.

RUBBING 0R POLISHING MACHINE.

APPLICATION 311.21) 001 .31. 1903.

N0 MODEL.

3 SHEETSSHEET 3.

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m: mums PETERS c0. PNOYO-LIYHO, WASHYNGTON. u. :2

UNITED STATES "Patented May 24, 1904.

PAT NT ()EEICE.

CHARLES s. YARNELL, or MINNEAPOLIS, MINNESOTA.

RUB BING OR POLISHING MACHINE.

SPECIFICATION forming part of Letters Patent No. 761,023, dated May 24,1904.

Application filed October 31, 1903.

To all whom it may concern.-

Be it known that I, CHARLES S. YARNELL, of Minneapolis, in the county ofHennepin, State of Minnesota, have invented certain new and usefulImprovements in Rubbing or Polishing Machines, of which the following isa specification.

This invention relates to rubbing and polishing machines designedespecially for sandpapering or polishing surfaces of wood, although themachine is capable without reconstruction of being used for rubbing orpolishing surfaces of other materials.

The object of my present invention is to provide a machine that iscapable of operating upon a large surface, whereby the plane surfaces ofwooden articles, such as table-tops,

I may be rapidly and economically finished.

Another object of the invention is to provide a machine that is easilyoperated and is simple and economical in construction.

In the accompanying drawings, forming part of this specification, Figure1 is a front elevation of a machine embodying my invention. Fig. 2 is aplan view of the same. Fig. 3 is a detail of a portion of the table.Fig. 4 is a detail section on line A 4 of Fig. 2. Fig. 5 is a transversesection on line 5 5 of Fig. 2. Figs. 6 and 7 are details of thepressure-plate and the means for controlling the same. Fig. 8 is adetail of the connection between the opcrating-lever and the barcarrying the pressure-plate. Fig. 9 is a detail of the means foradjusting the table.

In the drawings, 2 represents the frame of the machine, which is of anypreferred or suitable construction. This frame carries the horizontalrails or ways 1, upon which is supported by suitable wheels 3 thework-table 3. This table may be moved forward and back by hand beneaththe sanding or polishing belt. Arranged in the standards 2 are thethreaded shafts 4, suitably connected to the rails or Ways 4 (see Fig.9) and provided at their lower ends with sprocket-wheels 2', connectedthrough the base of the machine by a suitable sprocket-belt 2". One ofthe shafts 1 is provided with a beveled pinion 4:", arranged to beoperated by a crank-shaft 5, carrying a pinion that meshes with thepinion -ed a shaft 15.

Serial No. 179,274. (No model.)

1''. 2 By turning the crank-shaft 5 the rails or ways 4 and thework-table supported thereon may be raised or lowered, while at the sametime the table is maintained in a horizontal position.

The frame of the machine, the work-table, and the means for operatingthe same are substantially the same as the corresponding parts shown anddescribed in Letters Patent of the United States No. 743,608, issued tome November 10, 1903.

Secured upon the standards 2 are the horizontal bars or beams 6, whichare suitably secured at their ends to the upper portions of thestandards 2. Said beams are thus separated a distance substantiallyequal to the width of the upper end of each standard. Upon the beams 6at a point substantially over one of the standards I secure a plate 7carrying the shaft-boxes 8, in which is mounted a driving-shaft 9,having suitable fast and loose pulleyslO and 11. This shaft also carriesthe belt-pulley 12. The plate 7 is preferablyrigidly secured inposition. At the opposite end of the machine I provide a plate 13,

carrying shaft-boxes 1A, in which is mount- This shaft carries a pulley16, corresponding to the pulley 12. The plate 13 is preferably providedwith the longitudinal slots 17 and bolts 18 pass through these slots andsecure the plate in position. At the opposite edge of the plate Ipreferably provide a depending flange 19, through which extends 'thesescrews, which are mounted in lugs or standards 25 upon the plate 13, maybe used to adjust the plate 21 upon the stud 22. By this means the shaft15 may be adjusted so as to be exactly parallel with the shaft 9.Mounted upon the pulleys 12 and 16 is a suitable sandpaper or otherrubbing or polishing belt 25. It will be seen that the lower portion ofthis belt runs above and parallel with the top of the table 3, and Iprefer to provide means whereby pressure may be applied to this portionof the belt for the purpose of bringing the sanding or polishing surfacethereof upon the material to be operated upon and holding it there withany desired degree of pressure. For this purpose I arrange above thelower portion of the belt a horizontal bar 26. This bar, as here shown,is of rectangular form and provided with a series of vertical openingsthrough which extend the stems 27, that support the pressureplate 28.The plate 28 is preferably of substantially the width of the sanding 01'polishing belt and is arranged within and above the lower portion ofsaid belt, so that the belt travels in contact with the under surface ofsaid plate. The plate 28 is provided with a series of lugs 29, and saidlugs are adapted to engage suitable cross-bars 30, pivotally connectedto heads 31 upon the lower ends of the stems 27. The heads 31 areprovided with arms projecting over the bars 30, and suitable springs 32are arranged between the ends of said arms and said bars, being held inposi tion by suitable projections upon said arms and said bars.Adjusting-screws 33 extend through the ends of the arms 31, and by meansof said screws the bars 30, and with them the plate 28, may be adjusted.Secured to the under side of the bar 26 are a series of nuts 34, andthreaded sleeves 35 surround the stems 27 and engage said nuts 34.Springs 36 surround the stems 27 and are arranged between the sleeves 35and the heads 31.

With this construction it will be seen that by adjusting the sleeves 35the tension of the springs 36 may be increased or diminished at will.The upper end of each stem 27 is screwthreaded, and a threaded sleeve 37is arranged to engage the threaded end of the stem, said sleeve restingupon the top of the bar 26 and being provided with a suitable hand-wheel38. By means of the sleeve 37 the position of the bar 30 and the plate28 connected thereto may be regulated. I provide means also for raisingand lowering the bar 37 and with it the pressure-plate and connecteddevices. As here shown, a series of levers 40 are pivoted upon one ofthe beams-6 and extending forward are connected to the bar 26. I havehere shown each of the levers 40 provided with a fork at its forwardend, and this fork is made to engage" a collar 41, arranged upon acylindrical portion of the bar 26, the connection between said lever andsaid collar being made by suitable screws 42. (See Fig. 8.) The rearportions of the levers 40 are bent downward between the two beams 6, andeach of said levers is connected to a rod 41, and said rod is connectedby a link 43, which extends through an opening in the rear beam 6, witha lever 44, having secured thereto an arm 45, carrying an adjustablecounterweight 46. (See Fig. 5.) The lever 44 is pivoted in a lug 47,preferably secured upon the top of the forward beam 6. For the purposeof maintaining the bar 26 in a horizontal position as it is raised orlowered I prefer to provide upon said bar a lug 48 and upon the upperpart of the beam 6 a corresponding lug 49 and to connect these two lugsby a link 50. Then as the levers 40 are swung upon their pivots for thepurpose of raising and lowering the pressure-plate the link 50,connected to the lugs 48 and 49, prevents said bar from turning axially.

For the purpose of operating the pressure devices I provide anoperating-rod 51, connected to the lever 44 and extending forward of thetable of the machine. This rod carries the adjustable weight 52 and alsothe pivoted latch 53, which is adapted when the rod is raised to theposition shown in Fig. 5 to catch upon the top of the forward beam 6,and thereby to hold the rod 51 and the pressure-plate in an-elevatedposition. A cord 54 is preferably connected to the latch 53, and bymeans of this cord when it is desired to lower the pressure-plate, so asto bring the sanding or polishing belt in contact with work upon thetable, the latch is raised by means of the cord 54, and the operator canthen through the rod 51 operate the levers 41 and depress thepressure-plate, causing said plate to bear upon the'sanding or polishingbelt with any desired pressure and raising it therefrom at will. Thesanding or polishing belt is therefore under the direct control of theoperator at all times. A belt of considerable width may be employed, sothat a large surface of the material to be finished will be operatedupon, and therefore but a short time will be required to finish thesurface of the largest article that can be placed in the machine.

I prefer to provide upon each edge of the table 3 a threaded shaft 55,mounted in suitable bearings 56 and capable of being rotated by having acrank applied to the end of the shaft. Each of these shafts is providedwith a sprocket-wheel 57, and the two shafts are connected by thesprocket-chain 58, passing around said sprocket-wheels, so that saidshafts are rotated in unison. Arranged upon each of the threaded shaftsare the threaded blocks 59. (See Fig. 3.) These blocks are arranged atequal distances from the center of the table, and by rotating the shaftsthe blocks are simultaneously moved toward or from the center. Each ofsaid blocks is provided with a vertical opening, and arranged upon theupper surface of the table 3 are the work-holding bars 60. These barsare provided at their ends with the pins 61, adapted to enter theopenings in the threaded blocks 59. (See Fig. 3.) The bars maybe placedin position with their pins engaging the openings in the threadedblocks, and by rotating the threaded shafts the bars may be moved towardthe center of the table until their inner edges are brought in contactwith the edges of the table-top or other article to be operated upon.These bars will prevent the article from being movedout of position bycontact with the traveling belt therewith. I prefer to provide the tablewith the handles 63, by means of which the operator while controllingthe pressure on the belt through the rod 51 may move the table 3 backand forth beneath the belt, thereby bringing every portion of thearticle to be operated upon beneath the traveling belt.

The special advantages of this machine are found in its simplicity ofconstruction, ease of operation, and large capacity.

The pivotal yielding connection between the bars to which thepressure-plate is connected and the supporting-stems permit the plate toyield slightly when the belt is brought over an uneven surface, therebypreventing any excessive wear on the belt. The spring connection betweenthe heads and the supporting-bar also causes the pressure-plate to beheld against the belt at all times with a yielding pressure. 7

While the machine is designed especially for using a sandpaper belt andfor operating upon plane surfaces of wood, it is adapted for using anykind of rubbing or polishing belt and for operating upon any material.

It will be seen that the pressure-plate may readily be detached from thebars that are pivotally supported on the lower ends of the stems, and Ifind it advantageous to provide pressure-plates of different lengths,any one of which may be employed, according to the length of the articleto be finished.

I do not limit myself to the details of construction, as the same may bevaried in many particulars without departing from my invention.

I claim as my invention 1. The combination, in a machine of the classdescribed, with a rubbing and polishing belt and means for driving saidbelt, of a pressure-plate arranged within said belt and in proximity tothe operating portion thereof, a supporting-bar, connections betweensaid plate and said bar, pivoted levers connected with said bar, andmeans for operating said levers, thereby pressing said plate againstsaid belt, substantially as described.

2. The combination, in a machine of the class described, with a suitablework-supporting table, of a rubbing or polishing belt arranged tooperate upon the material supported upon said table, a pressure-platearranged within said belt and in proximity to its working portion, asupporting-bar, yielding connections between said plate and said bar,pivoted levers supporting said bar and an op erating-rod controllingsaid levers, substantially as described.

3. The combination, in a machine of the class described, with a suitableWork-supporting table, means for raising said table and means permittingsaid table to be moved horizontally, of a rubbing or polishing beltarranged to operate upon the material supported upon said table, apressure-plate arranged within said belt and in proximity to its workingportion, a supporting-bar, yielding connections between said plate andsaid bar, and operating-levers for raising and lowering said bar andsaid plate, whereby the plate may be pressed against the belt,substantially as described.

4:. The combination, in a machine of the class described, with therubbing or polishing belt, of the pressure-plate arranged within saidbelt and in proximity to its workingportion, a supporting-bar, pivotedstems supported upon said bar, detachable connections between said plateand said stems, and means for raising and lowering said bar,substantially as described. 5. The combination, in a machine of theclass described, with the rubbing or polishing belt, of a bar arrangedwithin said belt, pivoted levers supporting said bar, pivotalyieldingconnections between said bar and said pressure-plate, and acounterbalanced operating-rod for moving said levers.

6. The combination, in a machine of the class described, with thepressure-plate 28 and the bar 26, of the stems 27 adjustably supportedin said bar, the heads 31 secured upon said stems, the bars 30 pivotallyconnected to said heads, the springs 32 between said heads and saidbars, and the adjusting-screws 33, substantially as described.

7. The combination, in a machine of the class described, with a rubbingor polishing belt and means for operating the same, of the worksupporting table provided with the threaded shafts 55, extendingparallel with the edges of the table and at opposite sides thereof,means for operating said shafts, the work-holding bars 60, and suitableconnections between said bars and said shafts, for the purpose setforth.

In witness whereof I have hereunto set my hand this 20th day of October,1903.

CHARLES S. YARNELL.

In presence of A. 0. PAUL,

G. G. HANSON.

IIO

